It would be more accurate to say that some people use it as a simple turn of phrase without considering what it means. Language is made mostly of metaphor and analogy. Explaining something by comparison to something that is already understood is a technique that seems to fit our model of thought.

Over time the original meaning may fade or be forgotten, and the residual symbol in the language becomes the thing itself. Etymology is full of examples.

But that much history has not yet passed since the introduction of the term "curbstomping" and so using it is still a choice that conveys some meta-meaning about content and style.

As mentioned further up in the thread it is unnecessarily violent for conveying the meaning in the comment.